#shopping.py

def shop(where = 'store',what = 'apple',howmuch = '$10'):
    print('I want to ' + where + ' buy ' + what + ',but it’s ' + howmuch)


shop()

shop('龙翔市场')

shop('龙翔市场','馒头')

shop('龙翔市场','馒头','￥1')
